Welcome to the forums! Which 12 volt plug are you talking about? The one by the where the television is supposed to mount? Or a different one, not familiar with your specific unit. A picture might help too.

Those are an odd sized jack, for some unknown reason. A lot of standard 12 volt plugs don't fit them properly. Best bet would be to install a couple of new ones in a better location, not too hard to do. I like the Blue Sea stuff, but there are less expensive options out there.

While we're on this topic I thought I'd share this. One of my mod projects for this Spring is to install weather-resistant 12V outlets near the wheels to provide a convenient source of power for plugging my 12V tire inflator. I found these at my local Wally-world and I plan to drop 12V from the power distribution panel through an existing hole in the floor and splice these in. I plan to locate them in an area that should receive minimal splashing from the tires yet close enough for the inflator cord to reach.